The Relationship Between Chronic Myeloid Leukemia and the Ph1 Aberrant Chromosome
Chronic myeloid leukemia, medically also called chronic myelogenous leukemia and abbreviated as "CML," is a malignant tumor of the blood system. In more than 90% of CML patients, the erythroid, granulocytic, and megakaryocytic lineages all carry the Ph1 aberrant chromosome; medicine therefore infers that these three cell types derive from a common stem cell (a pluripotent stem cell capable of differentiating into many kinds of blood cells). It is precisely because this pluripotent stem cell develops the Ph1 aberrant chromosome that the red blood cells, granulocytes, and megakaryocytes differentiated from it all carry the Ph1 aberrant chromosome.
The Ph1 aberrant chromosome, also called the Philadelphia chromosome 1, is an abnormal chromosome formed by reciprocal translocation between the long arms of chromosome 9 and chromosome 22. It was first discovered in 1960 by the American physicians P. C. Nowell and D. A. Hungerford in patients with chronic myeloid leukemia. Because the Ph1 aberrant chromosome appears at a very high rate in CML patients, it has now become the core molecular marker for diagnosing CML.
Breakage of this chromosome causes recombination of the c-abl gene on chromosome 9 with the bcr gene on chromosome 22, forming the bcr/abl fusion gene, which encodes the P210, P190, or P230 protein, enhances tyrosine-kinase activity, and stimulates abnormal granulocyte proliferation—this is the cause of the excessive granulocyte proliferation in CML patients.
It is generally believed that this disease may be related to ionizing radiation and chemical exposure. Long-term, high-dose exposure to radiation such as the X-rays and CT used in medical examinations, frequent use of hair dyes (especially those containing aniline-type ingredients), and long-term contact with certain industrial chemicals may all cause this disease.
The course of CML passes through three stages: initially a relatively stable chronic phase, then possibly an accelerated phase, and finally a dangerous blast crisis. In the blast crisis, the patient's symptoms resemble those of acute leukemia. Overall, the disease progresses slowly; in the early stage the patient has mild or basically no symptoms, perhaps only fatigue and low fever. But the patient's immunity is low, making it easy to contract viral or bacterial infections in daily life and develop relatively severe post-infection symptoms.
Currently, Western medicine recommends targeted therapy with tyrosine-kinase inhibitors (such as imatinib) for this type of patient. TCM generally treats this disease by pattern differentiation as "consumptive detriment" (xu lao), combining support of the righteous root with dispelling pathogen. I myself have found that Chaihu-series formulas, combined with the TCM method of "attacking poison with poison" using insect herbs such as Wugong (Scolopendra), Quanxie (Scorpio), and Bihu (gecko), have some effect on this disease. They can prolong the patient's asymptomatic period and relieve or even eliminate the clinical symptoms of symptomatic patients. But a cure is still very difficult.